Renal transplantation
Outcome
Does Donor Nephron Mass Have Any Impact on Graft Survival?

https://doi.org/10.1016/j.transproceed.2007.03.084Get rights and content

Abstract

Objectives

Functioning nephron mass namely, the number of nephrons in the grafted kidney, is one of the nonimmunologic factors that may have some impact on long-term graft survival. The aim of this study was to assess the impact of donor nephron mass on graft outcome in the recipient.

Materials and Methods

From 1989 to 2005, 1000 renal transplants were performed at our center. The 217 studied cases were followed for an average of 8 years. All patients received grafts from living donors. The weight of the grafted kidney (donor nephron mass) as well as the recipient’s body mass index (BMI) were measured at the time of operation. Nephron mass index (NMI) was defined as the ratio of donor nephron mass to recipient BMI. Associations between variables were tested by logistic regression and Pearson correlation using the SAS system and S-plus statistical software. To evaluate graft function, we determined serum creatinine values, acute rejection episodes and chronic nephropathy.

Results

Mean NMI was 8.07 ± 0.2 and mean creatinine level was 1.43 ± 0.4 mg/dL. There were 32 cases (14.7%) of acute rejection, who were managed successfully with antithymocyte globulin (ATG) in 28 cases. Four patients lost their grafts. There were 15 cases (7%) of graft loss due to chronic rejection. Using Pearson correlation, we observed no association between NMI and mean serum creatinine level. Logistic regression showed a significant relation between NMI and acute rejection (P < .05) with an odds ratio of 2.0. There was no significant correlation between NMI and chronic rejection.

Conclusions

The lower the NMI, the greater the short-term graft loss. However, in the long term, no significant correlation was found between graft survival and NMI. Also, mean creatinine level was not significantly different among patients regardless of NMI.

Section snippets

Materials and Methods

Over a 16-year period (1989 to 2005), we performed 1000 renal transplantations including the 217 patients (96 females and 121 males) studied herein with follow-up for an average of 8 years (range, 1 to 16). All patients received grafts from living donors. The patients ages ranged from 12 to 72 years (average, 36 years). All patients received cyclosporine, mycophenolate mofetil (MMF), or azathioprine, and prednisolone. Graft kidney weights (donor nephron mass) and recipient BMI were measured at

Results

Average patient weight was 52 kg (range, 24 to 82). Patient height varied from 118 to 182 cm (mean, 158 cm). Average donor kidney weight (nephron mass) was 155 g (range, 100 to 190). Recipient BMI varied from 14 kg/m2 to 33 kg/m2 (mean, 19.2). Mean NMI was 8.07 (5.1 to 13.3), and mean creatinine level during follow-up was 1.43 mg/dL (0.6 to 2.3). There were 32 cases (14.7%) of acute rejection, which were managed successfully with antithymocyte globulin (ATG) in 28 cases and four patients lost

Discussion

In the past decade, several investigators have suggested that hyperfiltration injury from inadequate nephron mass may cause progressive injury in transplanted kidneys.1 Reduction in the functioning number of nephrons below 50% may induce glomerular hypertension and hyperfiltration in surviving units.4, 5 This effect may influence upregulation of surface molecules and cytokine production associated with macrophage infiltration. As a consequence, progressive functional and morphologic

References (16)

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Cited by (11)

  • Can the kidney weight and recipient body weight ratio predict long-term graft outcome in living donor kidney transplantation?

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    Size matching between a donor kidney and recipient body weight is considered to promote short- and long-tem graft function. The results of the present study correspond well with those of an earlier study in which the Kw/Rw ratio is correlated with long-term graft function but not related to the long-term graft failure.9 Lee et al5 reported that the volume of living donor kidneys can have a significant and independent impact on the 6 months post-transplantation.

  • Size does matter-donor-to-recipient body mass index difference may affect renal graft outcome

    2012, Transplantation Proceedings
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    More studies have focused on donor-to-recipient size differences. A low ratio of donor kidney to recipient body weight has been reported to be associated with worse short-term outcomes but not to affect long-term graft survival.8,9 Cho et al reported lower donor-to-recipient body surface area ratios to be related to worse 1-year graft survival.10

  • Size does matter: Donor renal volume predicts recipient function following live donor renal transplantation

    2011, Journal of Urology
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    The length of cold ischemia time in deceased donor renal transplantation is simply not seen with living donor transplantation, making the comparison between the 2 groups difficult. In another study by Taherimahmoudi et al nephron mass index was calculated by taking the weight of the donated kidney and dividing by the BMI of the recipient.17 While a low index was associated with short-term rejection, no significant correlations were found between the nephron mass index and serum creatinine or the incidence of chronic rejection.

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